Protective gas pressure-maintaining sealing structure in heat transfer tube

Abstract

The utility model provides a heat transfer tube internal protective gas pressure maintaining sealing structure, which comprises a heat transfer tube, an elastic sealing plug assembly and a one-way valve assembly, the one-way valve assembly is embedded in the elastic sealing plug assembly, and the one-way valve assembly is in sealing connection with an opening part of the heat transfer tube through the elastic sealing plug assembly. According to the utility model, the effect of keeping micro-positive pressure in the heat transfer pipe is achieved by utilizing the matching of elasticity and mechanical force of the two stages of elastic sealing plugs, the heat transfer pipe is prevented from being rusted in a common atmospheric environment, and the normal operation of nuclear power is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of material surface protection, in particular to a pressure-maintaining sealing structure for protective gas inside a heat transfer tube. Background Art

[0002] High temperature gas-cooled reactor is one of the advanced fourth generation nuclear power reactor technologies, with advantages such as good safety, high efficiency, good economy and wide application. The low temperature section of the spiral heat transfer tube for steam generator uses ASME SA-213 T22 low alloy steel, which is very easy to rust during the manufacturing, assembly and storage process, reducing product quality. Therefore, it is necessary to protect the inside of the ASMESA-213 T22 heat transfer tube with a slightly positive pressure (absolute pressure 1.2bar) of protective gas to prevent it from rusting in the normal atmospheric environment, thereby affecting the normal use of the heat transfer tube and thus avoiding the impact on the operation of nuclear power.

[0003] The Chinese patent document discloses "a sealing structure for a heating pipe", and its announcement number is CN 214274764U. The utility model includes a front connecting pipe, a rear connecting pipe, a front connecting threaded portion, a front heat-insulating shell, a first slide groove, a first clamping block, a groove, a clamping tooth, an air-leakage-proof sealing pipe, an air-leakage-proof filler, an air-leakage-proof sealing pipe cap, a rear connecting threaded portion, a rear heat-insulating shell, a second slide groove, a second clamping block, a ridge, a convex block and a tooth groove. The rear connecting pipe is arranged on the front connecting pipe and is threadedly connected. The front connecting threaded portion includes a sealing connection thread groove and a sealing gasket. The rear connecting threaded portion includes a sealing connection thread and a sealing gasket. The sealing structure of the heating pipe has poor sealing effect, wastes manpower and material resources, and is inconvenient to replace and disassemble the pipe, and achieves better sealing and saves resources. However, the sealing structure of the utility model cannot introduce protective gas and cannot be applied to the pressure-maintaining sealing of protective gas inside the heat transfer pipe. Utility Model Content

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the utility model is to provide a protective gas pressure-maintaining sealing structure inside a heat transfer tube, which is used to solve the problem that the inside of the existing heat transfer tube is rusted in a normal atmospheric environment, affecting the normal use of the heat transfer tube and affecting the operation of nuclear power.

[0005] To achieve the above-mentioned purpose and other related purposes, the utility model is implemented by including the following technical solutions.

[0006] The utility model provides a heat transfer tube internal protective gas pressure-maintaining sealing structure, comprising a heat transfer tube, an elastic sealing plug assembly and a one-way valve assembly, wherein the one-way valve assembly is embedded in the elastic sealing plug assembly, and the one-way valve assembly is sealed and connected to the opening of the heat transfer tube through the elastic sealing plug assembly.

[0007] The present application injects protective gas into the heat transfer tube through a one-way valve assembly, and realizes pressure-maintaining sealing of the protective gas inside the heat pipe in combination with the sealing connection of the elastic sealing plug assembly. This structure can protect the heat transfer tube with a positive pressure (absolute pressure 1.2 bar) of protective gas to prevent it from rusting in a normal atmospheric environment, thereby ensuring the normal operation of nuclear power.

[0008] Preferably, the one-way valve assembly includes an adapter and a core body and a core rod arranged in the adapter, the core body has an injection channel, the core rod is accommodated in the injection channel, and can move axially in the injection channel; the core rod includes a sealing portion arranged on the outside of one end of the injection channel and an adjusting portion arranged on the outside of the other end of the injection channel; the sealing portion is in a first position when in contact with the injection channel, and is in a second position when separated from the injection channel; in the second position, gas can enter the heat transfer tube from the injection channel; in the first position, the core rod achieves sealing of the injection channel through the cooperation of the sealing portion and the core body.

[0009] Preferably, a first sealing ring is provided on a side of the sealing portion close to the core body.

[0010] Preferably, a limiting groove is provided on the outer wall of one end of the core body embedded in the adapter, and a second sealing ring is provided in the limiting groove.

[0011] Preferably, the elastic sealing plug assembly comprises a primary elastic sealing plug sealedly connected to the opening of the heat transfer tube, and the adapter is embedded in the primary elastic sealing plug.

[0012] Preferably, the adapter is embedded in the first-level elastic sealing plug and one end thereof passes through the first-level elastic sealing plug, and a limiting boss is formed at the end, and a second-level elastic sealing plug is also provided between the limiting boss and the first-level elastic sealing plug. The second-level silicone plug design of the present application can expand the outer diameter of the first-level elastic sealing plug based on the second-level elastic sealing plug squeezing the first-level elastic sealing plug outward from the inside, thereby increasing the friction between the first-level elastic sealing plug and the inner wall of the heat transfer tube, and improving the pressure-maintaining sealing performance of the protective gas inside the heat transfer tube.

[0013] Preferably, a seal is provided at the contact gap between the other end of the adapter and the primary elastic sealing plug to prevent gas leakage at the contact gap and further improve the pressure-maintaining seal of the protective gas inside the heat transfer tube.

[0014] Preferably, the core body is fixedly connected to the adapter, and the adjusting member can move axially along the core rod relative to the core body to control the opening and closing of the gas injection channel.

[0015] Preferably, the end of the adjusting member close to the gas injection channel is provided with a conical surface, and the conical surface can be screwed in and out relative to the gas injection channel to control the opening and closing of the gas injection channel. The conical surface design facilitates the screwing in and out of the adjusting member in the gas injection channel, has strong operability, and good sealing performance.

[0016] Preferably, the outer wall of the core body is threadedly connected to the inner wall of the adapter, which is convenient for assembly and has good stability.

[0017] Preferably, the inner wall of the adjusting member is threadedly connected to the outer wall of the core rod, which is convenient for assembly and has good stability.

[0018] As described above, the heat transfer tube internal protective gas pressure-maintaining sealing structure of the utility model has the following beneficial effects: protective gas is injected into the heat transfer tube through the one-way valve assembly, and the protective gas pressure-maintaining sealing inside the heat transfer tube is realized in combination with the sealing connection of the elastic sealing plug assembly; the secondary silicone plug design can be based on the secondary elastic sealing plug inside to squeeze the primary elastic sealing plug outward to expand the outer diameter of the primary elastic sealing plug, increase the friction between the primary elastic sealing plug and the inner wall of the heat transfer tube, and improve the pressure-maintaining sealing of the protective gas inside the heat transfer tube. This structure utilizes the elasticity and mechanical force of the two-stage elastic sealing plug to achieve the effect of maintaining a slight positive pressure inside the heat transfer tube, preventing it from rusting in the normal atmospheric environment and ensuring the normal operation of nuclear power. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It shows a schematic diagram of the gas injection state of the protective gas pressure-maintaining sealing structure inside the heat transfer tube.

[0020] Figure 2 It shows a schematic diagram of the sealing state of the protective gas pressure-maintaining sealing structure inside the heat transfer tube.

[0021] Figure 3 Shown is a schematic diagram of the original state of the primary elastic sealing plug.

[0022] Figure 4 It is a schematic diagram showing the state after the primary elastic sealing plug is squeezed by the secondary elastic sealing plug.

[0023] Explanation of the accompanying drawings: 1. heat transfer tube; 2. adapter; 3. core body; 4. core rod; 5. gas injection channel; 6. sealing part; 7. adjusting part; 8. first sealing ring; 9. limiting groove; 10. second sealing ring; 11. primary elastic sealing plug; 12. limiting convex ring; 13. limiting boss; 14. secondary elastic sealing plug; 15. conical extrusion surface; 16. sealing part; 17. conical surface. DETAILED DESCRIPTION

[0024] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0025] See also Figures 1 to 4 It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change in the proportion relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the utility model without affecting the effects and purposes that can be achieved by the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the utility model without substantially changing the technical content.

[0026] like Figure 1 and Figure 2 As shown, the utility model provides a heat transfer tube internal protective gas pressure-maintaining sealing structure, comprising a heat transfer tube 1, an elastic sealing plug assembly and a one-way valve assembly, wherein the one-way valve assembly is embedded in the elastic sealing plug assembly, and the one-way valve assembly is sealed and connected to the opening of the heat transfer tube through the elastic sealing plug assembly, and the one-way valve assembly comprises an adapter 2 and a core body 3 and a core rod 4 arranged in the adapter, wherein the core body has an injection channel 5, and the core rod is accommodated in the injection channel and can axially move in the injection channel; the core rod comprises a gas injection channel 5, wherein the core rod is arranged in the injection channel 5, and the core rod is arranged in the ... The sealing part 6 outside one end of the channel and the adjusting part 7 outside the other end of the gas injection channel, the adjusting part is provided with a conical surface 17 at one end close to the gas injection channel, the conical surface can be rotated in and out relative to the gas injection channel to control the opening and closing of the gas injection channel; the sealing part is in the first position when it is in contact with the gas injection channel, and the sealing part is in the second position when it is separated from the gas injection channel; in the second position, the gas can enter the heat transfer tube from the gas injection channel; in the first position, the core rod realizes the sealing of the gas injection channel through the cooperation between the sealing part and the core body. The sealing part is provided with a first sealing ring 8 on the side close to the core body.

[0027] The outer wall of one end of the core body embedded in the adapter is provided with a limiting groove 9, and a second sealing ring 10 is provided in the limiting groove. The elastic sealing plug assembly includes a primary elastic sealing plug 11 which is sealed and connected to the opening of the heat transfer tube, and the adapter is embedded in the primary elastic sealing plug. The end of the primary elastic sealing plug is provided with a limiting convex ring 12 in the circumferential direction. The adapter is embedded in the primary elastic sealing plug, and one end passes through the primary elastic sealing plug, and a limiting boss 13 is formed at the end. A secondary elastic sealing plug 14 is also provided between the limiting boss and the primary elastic sealing plug, and a conical extrusion surface 15 with a gradually decreasing diameter is provided at one end of the secondary elastic sealing plug close to the primary elastic sealing plug. A sealing member 16 is provided at the contact gap between the other end of the adapter and the primary elastic sealing plug. The outer wall of the core body is threadedly connected to the inner wall of the adapter, and the inner wall of the adjusting member is threadedly connected to the outer wall of the core rod. The adjusting member can move axially along the core rod relative to the core body to control the opening and closing of the gas injection channel.

[0028] The working principle of the utility model is as follows:

[0029] Unscrew the seal 16, pass the adapter 2 of the one-way valve assembly through the primary elastic sealing plug 11, so that the primary elastic sealing plug 11 contacts the secondary elastic sealing plug 14, and put the seal 16 on the surface of the adapter 2 to complete the assembly of the elastic sealing plug assembly. At this time, the state of the primary elastic sealing plug 11 is as follows: Figure 3 shown.

[0030] Insert the primary elastic sealing plug 11 into the opening of the heat transfer tube 1, and tighten the sealing member 16 to press the primary elastic sealing plug 11 downward, so that the inner surface of the primary elastic sealing plug 11 is pressed against the conical extrusion surface of the secondary elastic sealing plug 14. At this time, the state of the primary elastic sealing plug 11 is as follows: Figure 4 As shown, the outer diameter of the primary elastic sealing plug 11 is expanded due to the internal expansion, forming a compressed contact surface with the inner wall of the heat transfer tube 1, thereby achieving sealing.

[0031] The adjusting member 7 is screwed out along the core rod 4 in the direction away from the core body 3 to open the gas injection channel 5. Figure 1 In the second position shown in FIG. 1 , a slightly positive pressure protective gas (such as N2) is injected into the heat transfer tube 1 from the gas injection channel 5. The gas pressure inside the heat transfer tube 1 increases, driving the core rod 4 to push upward, so that the sealing portion 6 closes the gas injection channel 5. At this time, Figure 2 In the first position shown, the first sealing ring 8 is squeezed and sealed with the bottom of the core 3 to improve the sealing performance of the gas injection channel 5 and realize the pressure-maintaining seal of the protective gas inside the heat transfer tube.

[0032] In summary, the utility model injects protective gas into the heat transfer tube through the one-way valve assembly, and realizes the pressure-maintaining seal of the protective gas inside the heat pipe in combination with the sealing connection of the elastic sealing plug assembly; the secondary silicone plug design can expand the outer diameter of the primary elastic sealing plug based on the secondary elastic sealing plug squeezing the primary elastic sealing plug outward from the inside, thereby increasing the friction between the primary elastic sealing plug and the inner wall of the heat transfer tube, and improving the pressure-maintaining seal of the protective gas inside the heat transfer tube. This structure utilizes the elasticity and mechanical force of the two-stage elastic sealing plug to achieve the effect of maintaining a slight positive pressure inside the heat transfer tube, preventing it from rusting in a normal atmospheric environment, and ensuring the normal operation of nuclear power. Therefore, the utility model effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0033] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A heat transfer tube internal protective gas pressure-maintaining sealing structure, characterized in that: It comprises a heat transfer tube (1), an elastic sealing plug assembly and a one-way valve assembly, wherein the one-way valve assembly is embedded in the elastic sealing plug assembly, and the one-way valve assembly is sealed and connected to the opening of the heat transfer tube via the elastic sealing plug assembly.

2. The heat transfer tube internal protective gas pressure-maintaining sealing structure according to claim 1, characterized in that: The one-way valve assembly comprises an adapter (2), a core body (3) and a core rod (4) arranged in the adapter, the core body having an injection channel (5), the core rod being accommodated in the injection channel and being movable axially in the injection channel; the core rod comprising a sealing portion (6) arranged outside one end of the injection channel and an adjusting portion (7) arranged outside the other end of the injection channel; the sealing portion is in a first position when in contact with the injection channel, and is in a second position when separated from the injection channel; in the second position, gas can enter the heat transfer tube from the injection channel; in the first position, the core rod seals the injection channel through the cooperation of the sealing portion and the core body.

3. The heat transfer tube internal protective gas pressure-maintaining sealing structure according to claim 2, characterized in that: A first sealing ring (8) is provided on one side of the sealing portion close to the core body.

4. The heat transfer tube internal protective gas pressure-maintaining sealing structure according to claim 2, characterized in that: A limiting groove (9) is provided on the outer wall of one end of the core body embedded in the adapter, and a second sealing ring (10) is provided in the limiting groove.

5. The heat transfer tube internal protective gas pressure-maintaining sealing structure according to claim 2, characterized in that: The elastic sealing plug assembly comprises a primary elastic sealing plug (11) which is sealed to the opening of the heat transfer tube, the adapter is embedded in the primary elastic sealing plug, and a limiting convex ring (12) is provided around the end of the primary elastic sealing plug.

6. The heat transfer tube internal protective gas pressure-maintaining sealing structure according to claim 5, characterized in that: The adapter is embedded in the primary elastic sealing plug and one end thereof passes through the primary elastic sealing plug, and a limiting boss (13) is formed at the end thereof. A secondary elastic sealing plug (14) is also provided between the limiting boss and the primary elastic sealing plug. The secondary elastic sealing plug is provided with a tapered extrusion surface (15) with a gradually decreasing diameter at one end thereof close to the primary elastic sealing plug.

7. The heat transfer tube internal protective gas pressure-maintaining sealing structure according to claim 6, characterized in that: A sealing member (16) is provided at the contact gap between the other end of the adapter and the primary elastic sealing plug.

8. The heat transfer tube internal protective gas pressure-maintaining sealing structure according to claim 2, characterized in that: The core body is fixedly connected to the adapter, and the adjusting member can move axially along the core rod relative to the core body to control the opening and closing of the gas injection channel.

9. The heat transfer tube internal protective gas pressure-maintaining sealing structure according to claim 8, characterized in that: A conical surface (17) is provided at one end of the regulating member close to the gas injection channel, and the conical surface can be rotated in and out relative to the gas injection channel to control the opening and closing of the gas injection channel.

10. The heat transfer tube internal protective gas pressure-maintaining sealing structure according to claim 9, characterized in that: The outer wall of the core body is threadedly connected to the inner wall of the adapter; the inner wall of the adjustment part is threadedly connected to the outer wall of the core rod.

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